1. Field of the Invention
This invention relates to a filter plate for removing hydrocarbons and other contaminants from aqueous solutions and gases that relies on filtering the solution or gas through a filtering material supported by the plate of this invention provided with rows of linear substantially perpendicular openings. The present design of the filter plate is an improvement over prior art filter plates and is especially designed to reduce clogging due to accumulation of sludge and impurities. In addition, this invention relates to an apparatus for filtering an aqueous solution such as water and a gas such as air which utilizes the filter plate of the invention and to a method of removing hydrocarbons and other contaminants from, e.g., an aqueous solution or a gas such as air by passing the solution or the gas through a filtering material supported by the filter plate of the invention. This invention also relates to the use of the filter plate and apparatus for the removal of hydrocarbons and other contaminants from, a solution or a gas, particularly for decontaminating subsurface water and air.
2. Description of the Background
The purification of water is of importance, particularly water that is to be recycled for drinking and/or further domestic utilization.
Different kinds of contaminants are present in water and air which need to be substantially reduced or eliminated therefrom. For example, hydrocarbons and other contaminants such as solvents, particles such as dust, and the like, are harmful if present in air and water above a certain level. In order for water or air to become pure once again, the hydrocarbons and other contaminants must be substantially removed.
The prior art typically filtered water and/or air utilizing filters with openings that are spherical in nature. These tend to collect sludge over the round apertures, which clog the filter after a period of time.
Filters having apertures of different shapes are known in the art for applications other than the purification of water. For instance, Italian Patent No. 351,812 to Hagen and Luschel discloses a filter specifically suited for the preparation of coffed or other beverages like tea, and the like. The filter described in this patent has capillary cuts forming a 90.degree. angle that are positioned symmetrically opposite one another.
U.S. Pat. No. 2,345,080 to Ardenne describes an arrangement for producing filters by making fine perforations in foil by means of ion rays.
U.S. Pat. No. 1,092,719 discloses a separator flume having a false bottom provided with triangular openings, each having a depressed lip at its base, the free end of the lip terminating at the base of the triangle and extending toward the opening. The apparatus described in this patent is intended for washing and separating sand and gravel and freeing the gravel from foreign matter.
Accordingly, there is still a need for an improved filter plate for use in the removal of hydrocarbons and other contaminants from water and gases that reduces clogging due to sludge and contaminant retention on the filter plate.